netanyahu met with hillary clinton on thursday. margaret brennan watched the speech at the united nations. good morning. >> good morning, charlie, the israeli prime minister made a very public appeal to the u.n. to set a firm ultimatum to stop iran's nuclear development. he put pressure on the obama administration to take a tougher tone weeks ahead of the u.n. general election. >> israel's rhetorical red line. >> a red line should be drawn right here. >> became a literal one as prime minister benjamin netanyahu took to the u.n. general assembly with a red marker and a chart that says is iran's progress toward a nuclear weapon. >> red lines prevent war and faced with a clear red line, iran will back down. >> the prime minister's speech put in stark relief the differences between how the u.s. and israel views the threat of a nuclear iran. >> a nuclear armed iran is not a challenge that can be contained. >> reporter: while president obama says he will not allow iran to gain nuclear weapons, he hasn't publicly declared a point of no re